Field of the Invention
The present invention relates to a novel .alpha.2.fwdarw.3 sialyltransferase, DNA encoding the .alpha.2.fwdarw.3 sialyltransferase, a recombinant vector in which the DNA is incorporated and a cell containing the recombinant vector as well as a process for producing them. Further, the present invention relates to processes for synthesizing a sugar chain and attaching sialic acid to a sugar chain using the .alpha.2.fwdarw.3 sialyltransferase of the present invention and processes for synthesizing a sugar chain and attaching sialic acid to a sugar chain by expressing the .alpha.2.fwdarw.3 sialyltransferase of the present invention in a transformed cell. Further, the present invention relates to a method for detecting or inhibiting the expression of the .alpha.2.fwdarw.3 sialyltransferase of the present invention by using cDNA encoding the .alpha.2.fwdarw.3 sialyltransferase of the present invention. The .alpha.2.fwdarw.3 sialyltransferase of the present invention is useful for attaching sialic acid to a sugar chain and thereby obtaining useful physiological activity, and modifying a sugar chain which is attached to a useful physiologically active protein.